#define _CRT_SECURE_NO_WARNINGS 1 	
#include<stdio.h>
int main()
{
	int a = 0,b =0 ,c =0 ,r=0;
	scanf("%d%d", &a, &b);
	do 
	{
		r = a % b;
		if (r == 0)
			break;
		else 
		{
			c = a;
			a = b;
			b = r;
		}
	} while (r != 0);
	printf("%d", b);
	return 0;
}

